You cannot synchronize counter input applications using implicit timing in the same sense as analog input or output applications. These types of counter input applications cannot be programmed to make their measurements at the same time because the signals being measured themselves determine when the measurements are made, and there is no reason to set up multiple devices to measure the same signal. You also cannot use Start Triggers for these applications.

You can, however, ensure that all counters are using the same timebase for their input measurements by sharing the CI Counter Timebase signal. Program all devices to use the same signal (usually the 20MHzTimebase from one of the devices) as their CI Counter Timebase. More generally, one device can be queried for its CI Counter Timebase source and that terminal can be set as the source of the CI Counter Timebase for the other devices.

To synchronize Sample Clock-timed buffered counter input applications, use Sample Clock synchronization. The Sample Clock must be externally supplied to one of your devices. The other synchronized devices are programmed to use as their Sample Clock the CtrnGate signal, where n is the number of the counter.

To synchronize pulse generation counter output applications, share the CO Counter Timebase and Start Trigger signal. Program all devices to use the same signal (usually the 20MHzTimebase from one of the devices) as their CO Counter Timebase. More generally, one device can be queried for its CO Counter Timebase source and that terminal can be set as the source of the CO Counter Timebase for the other devices. Program all devices to use the same signal as their Digital Edge Start Trigger. This is typically the CtrnGate signal from one of the devices, where n is the number of the counter.